Ether and Energy in Eyolltion of Matter 5 



and helium agree thus, but they are scarce. Only two elements, 

 mercury and bromine — ^both of infrequent occurrence — are 

 Hquid at ordinary temperatures. The majority are sohds, 

 and are either abundant and widely diffused, like carbon, 

 sulphur, sihcon, and many of the metals, or are relatively 

 scarce, hke the greater number of the metals, and in some 

 cases are strikingly related to living bodies, like sulphur, iodine, 

 and phosphorus. 



By far the most abundant of the elements in organic bodies 

 are carbon, hydrogen, oxygen, and nitrogen, all characteristic 

 non-metallic bodies. As pointed out by H. Spencer (7; 4-10), 

 the first of these shows a remarkable relation to the other three. 

 Carbon is not only allomorphic as occurring naturally in the 

 forms of charcoal, graphite, and diamond; it is also soHd at 

 ordinary and even high temperatures. It likewise shows a 

 striking degree of molecular stabihty and cohesion, since it 

 unites wdth oxygen at a rather high temperature, it unites 

 with difficulty with hydrogen, and still less readily with nitro- 

 gen. It might thus be termed the passive element of funda- 

 mental strength and tenacity, which acts as the basis for most 

 organic molecules, and which caused organic chemistry, at 

 an earlier stage of its history, to be spoken of as "the chemistry 

 of the carbon compounds." 



Hydrogen, oxygen, and nitrogen, in marked contrast to 

 carbon, are gaseous, mobile, and amongst the lightest of ele- 

 ments. But even these are diverse in behavior. Nitrogen is 

 extremely inert chemically, and only when united T\'ith oxygen, 

 or to a less degree with hydrogen, does it show a marked capac- 

 ity for chemical unions with other elements. But, given the 

 formation of these, the resulting bodies are often of most un- 

 stable equihbrium, or even readily and violently explosive. 

 Hydrogen, though less inert than the last, only shows high 

 chemical activity when in presence of oxygen, but then takes 

 part with it, and by aid of it and carbon forms many sub- 

 stances, particularly those of organic origin. Oxygen, while 

 gaseous, light, and mobile in physical relation, exhibits on the 

 other hand extreme chemical activity, and might A\'ell be re- 



